1 /* SPDX-License-Identifier: GPL-2.0-or-later * 1
2 /*
3 * Generic C implementation of atomic counter
4 * machine independent code.
5 *
6 * Copyright (C) 2007 Red Hat, Inc. All Rights
7 * Written by David Howells (dhowells@redhat.c
8 */
9 #ifndef __ASM_GENERIC_ATOMIC_H
10 #define __ASM_GENERIC_ATOMIC_H
11
12 #include <asm/cmpxchg.h>
13 #include <asm/barrier.h>
14
15 #ifdef CONFIG_SMP
16
17 /* we can build all atomic primitives from cmp
18
19 #define ATOMIC_OP(op, c_op)
20 static inline void generic_atomic_##op(int i,
21 {
22 int c, old;
23
24 c = v->counter;
25 while ((old = arch_cmpxchg(&v->counter
26 c = old;
27 }
28
29 #define ATOMIC_OP_RETURN(op, c_op)
30 static inline int generic_atomic_##op##_return
31 {
32 int c, old;
33
34 c = v->counter;
35 while ((old = arch_cmpxchg(&v->counter
36 c = old;
37
38 return c c_op i;
39 }
40
41 #define ATOMIC_FETCH_OP(op, c_op)
42 static inline int generic_atomic_fetch_##op(in
43 {
44 int c, old;
45
46 c = v->counter;
47 while ((old = arch_cmpxchg(&v->counter
48 c = old;
49
50 return c;
51 }
52
53 #else
54
55 #include <linux/irqflags.h>
56
57 #define ATOMIC_OP(op, c_op)
58 static inline void generic_atomic_##op(int i,
59 {
60 unsigned long flags;
61
62 raw_local_irq_save(flags);
63 v->counter = v->counter c_op i;
64 raw_local_irq_restore(flags);
65 }
66
67 #define ATOMIC_OP_RETURN(op, c_op)
68 static inline int generic_atomic_##op##_return
69 {
70 unsigned long flags;
71 int ret;
72
73 raw_local_irq_save(flags);
74 ret = (v->counter = v->counter c_op i)
75 raw_local_irq_restore(flags);
76
77 return ret;
78 }
79
80 #define ATOMIC_FETCH_OP(op, c_op)
81 static inline int generic_atomic_fetch_##op(in
82 {
83 unsigned long flags;
84 int ret;
85
86 raw_local_irq_save(flags);
87 ret = v->counter;
88 v->counter = v->counter c_op i;
89 raw_local_irq_restore(flags);
90
91 return ret;
92 }
93
94 #endif /* CONFIG_SMP */
95
96 ATOMIC_OP_RETURN(add, +)
97 ATOMIC_OP_RETURN(sub, -)
98
99 ATOMIC_FETCH_OP(add, +)
100 ATOMIC_FETCH_OP(sub, -)
101 ATOMIC_FETCH_OP(and, &)
102 ATOMIC_FETCH_OP(or, |)
103 ATOMIC_FETCH_OP(xor, ^)
104
105 ATOMIC_OP(add, +)
106 ATOMIC_OP(sub, -)
107 ATOMIC_OP(and, &)
108 ATOMIC_OP(or, |)
109 ATOMIC_OP(xor, ^)
110
111 #undef ATOMIC_FETCH_OP
112 #undef ATOMIC_OP_RETURN
113 #undef ATOMIC_OP
114
115 #define arch_atomic_add_return
116 #define arch_atomic_sub_return
117
118 #define arch_atomic_fetch_add
119 #define arch_atomic_fetch_sub
120 #define arch_atomic_fetch_and
121 #define arch_atomic_fetch_or
122 #define arch_atomic_fetch_xor
123
124 #define arch_atomic_add
125 #define arch_atomic_sub
126 #define arch_atomic_and
127 #define arch_atomic_or
128 #define arch_atomic_xor
129
130 #define arch_atomic_read(v)
131 #define arch_atomic_set(v, i)
132
133 #endif /* __ASM_GENERIC_ATOMIC_H */
134
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